This invention relates to reflectors of the type that are used in combination with an emitter or collector to reflect radio or higher frequency electromagnetic energy and, more specifically, to reflectors used for spacecraft and other applications where the antenna reflector must be stowed in a relatively small package prior to deployment.
Spacecraft reflectors must satisfy a variety of difficult functional requirements, including stowage into a relatively small package during the launch phase, followed by deployment into a configuration suitable for operation in space on a satellite. As frequencies of interest have increased, including the use of such reflectors for light collection, many reflector constructions previously used, such as mesh grids and mechanical structures comprising many individual plates, have not proved suitable for these applications. Reflectors for high frequency radio waves and light collection require very tight control of tolerances on the reflector surface and previous reflector designs have not been capable of providing such tight tolerances while still being stowable into a relatively small package prior to deployment.
Specifically, utilization of microwave frequencies and visible light frequencies for communication systems for satellites and other advanced purposes means that in many cases tolerances on the reflector surface must not exceed plus or minus small fractions of a wavelength in order to prevent distortion of the signals or loss of signal to noise ratio. Previous reflector designs have only been able to achieve these kinds of accuracies with either single piece reflectors or reflectors with articulating panels and complex mechanisms to assure proper alignment of the panels in their deployed positions. Both of these concepts have proved adequate for certain purposes, but they remain extremely limiting in terms of their stowed to deployed envelope ratio and the tradeoffs of mechanical complexity versus accuracy of the deployed surface. Thus, there remains the requirement for a deployable reflector concept with very high surface accuracy and a high deployed to stowed envelope ratio.